Question: $ \left(\dfrac{256}{81}\right)^{-\frac{1}{4}}$
Solution: $= \left(\dfrac{81}{256}\right)^{\frac{1}{4}}$ Figure out what goes in the blank: $\Big(? \Big)^{4}=\dfrac{81}{256}$ Figure out what goes in the blank: $\Big({\dfrac{3}{4}}\Big)^{4}=\dfrac{81}{256}$ So $\left(\dfrac{256}{81}\right)^{-\frac{1}{4}}=\left(\dfrac{81}{256}\right)^{\frac{1}{4}}=\dfrac{3}{4}$